Chariot (oz2576)

About this Plan

Mac's Chariot. Rudder only RC sports model, with unusual power-pod style engine mount. For .19 to .29 power. From American Modeler, April 1957.

Quote: "Just what the doctor ordered for the AMA's new Pylon Racing Event, this remarkable radio plane is perfect for rudder-only work. Chariot, by Claude McCullough.

The original Chariot was built primarily as a sport flying model for use at R/C picnic and evening fly-for-fun sessions and the unusual layout was chosen mainly on the basis of its appeal as an interesting, out-of-the-rut project. Considering this background, I was agreeably surprised to find that the design has performance features which alone make the high thrust line conformation something for more radio control fans to sample.

Most valuable characteristic is the penetrating ability in a high wind, something very necessary to successful rudder-only performance. Chariot will stick her nose into a stiff breeze and make headway when a more conventional job will not.

Next noticeable feature is maneuvering ability with smooth, on-the-track turns without bouncy entry and pull-out. No design of equivalent size that I have flown could handle power so well. The prototype uses a .23 run full-out and I don't doubt that it could manage a .29 if necessary.

Needless to say, it is a rare day when a prop is broken. Not that this can be considered a lesser advantage - as any R/C flier who has to add a half a dozen broken props to a day's fuel and battery bill can testify.

The prototype model was built from selected hard balsa, carries copious battery and equipment choices, topped by multiple coats of dope and at 20 oz per sq ft wing loading can hardly be considered acrobatic. Still it is evident that a plane built to a lower weight with light equipment could more than hold its own competitively. In particular the performance suggests itself as just the ticket for the new AMA Pylon Racing Event.

Modelers who see the ship for the first time invariably marvel at the pylon being able to stay in one piece, since on the original version it is made from three laminations of 1/8 balsa. The secret is the special rock hard grade from a stock Frank Zaic selected for me some years ago.

At the annual Iowa R/C picnic I got to thinkering (as is my unfortunate habit) with previously worked out adjustment and snapped stalled the ship in under full power. The pylon, then fastened only at the top and bottom of the cabin, was thrown completely clear of the ship, but was not damaged at all. In repairs, 1/4 in sheet wedges filled-in to the bulkheads in front and to the rear (as shown on the plan) were added and no further trouble has been encountered despite my uncoordinated style of operation, which gives the ship more than its share of hard knocks.

Because of the certainty that the quality of wood I had is not commercially available now, plan shows a 1/8 plywood center with ordinary 1/8 hard balsa outside. This provides a pylon of similar weight and possibly greater strength with the addition of a more positive motor anchorage point.

For the average version of the Chariot I would suggest a .19 motor. If you incline to heavy batteries and lots of dope, a .23 will be best. For lightweights with small radios a .15 cubic incher may be fitted but I would not recommend anything smaller.

In construction I made use of one of Frank Zaic's neat aids to modeldom, the 60 in R/C Wing-Stab Kit. This ingenious shortcut comes with die-cut ribs, shaped leading and trailing edges, etc; besides saving construction time is of the usual high quality wood that has characterized FZ's productions. This item is sold only by mail and is available frosm Model Aircraft Co, Box 333, Station D, New York 3, NY for $3.50 postpaid. If you wish to build your own wing and stab from stock wood, full details appear on the plans.

In a ship of this type one consideration must be kept in mind. To keep the CG in the proper spot, weight should be concentrated in the nose and saved wherever possible in the tail. Don't spare anything forward of the wing. Use the heaviest balsa and plenty of cement. This has a practical as well as aerodynamic application. The nose section takes bumps and thumps of ordinary flying that in a conventional design are mainly absorbed by the motor-firewall unit, and the extra strength is as necessary as the weight. To the rear select lightweight wood and go easy on cementing, this section is not subject to very much strain and will not require additional strength.

My version used the McNabb 465-mc CR receiver - nice deal for sport flying because you can get many more flights logged by using the less crowded band and with little chance of interference. Proportional pulse is standard as far as I am concerned for rudder only flying and the results of the Nats R/C events give plenty of support for that preference. If you prefer another type of control there is ample space for mounting avail-able in the actuator compartment. Cabin and nose battery box are both of dimensions that easily accommodate any standard single channel unit and most small multi-channel outfits. Because the choice of mounting is so dependent on the receiver and personal prejudice of the individual constructor, I have not specified any particular receiver installation - you can easily adapt your favorite setup..."

Direct submission to Outerzone.

Update 06/02/2019: Added article, thanks to RFJ.

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